INHIBITION OF PHYSIOLOGICAL GROWTH HORMONE SECRETION BY ATROPINE

Abstract

The effects of atropine (specific muscarinic cholinergic inhibition) on the nocturnal secretion of GH [growth hormone] during the 1st cycle of stage IV sleep in 6 normal volunteers and 3 tall adolescents were investigated. Atropine was administered orally in a dose of 0.6 mg (n = 8) or 1.8 mg (n = 4) 30 min before expected sleep and the sampling repeated. Peak GH level without atropine was 45.3 mU/l (range 5.7 to 92.0); both doses of atropine abolished sleep associated GH secretion. Spontaneous daytime GH secretion was demonstrated during five 6 h sampling periods in 3 normal adults. There was a significant decrease in spontaneous daytime GH secretion when the sampling was repeated after atropine 0.6 mg of 1.8 mg. Apparently, inhibition of GH secretion using anticholinergic drugs should be further investigated in the management of excessive growth hormone secretion.